The mechs of the ruined planet GoBotron are cyborgs. In ancient times, they were organic humanoids, similar to Earthlings, but when cataclysm overtook their world, they survived by replacing their organic bodies with robotic components. Eventually, most GoBots were almost completely robotic; mechanical bodies housing a stabilized organic brain.
With time, they acclimated to their new form of existence. In time, many took on larger forms, with the ability to convert into vehicles. Some of these found their way to Cybertron, where they lived as refugees in any cities that would permit them.